Best piece of advice I can say is to take pictures so we can help with the prognosis. Giving us simple intel can help. But most outer barrels don't make a complete lock in on the receiver, in this case you need to go as tight as you can while still maintaining the hop up integrety and making sure that it'll sit in just even, along with mags and the like.
If the bolt is locking in place, maybe a sear got too far up into it, and perhaps you need to look at your trigger assembly before mounting it, but maybe you need to try with a little bit more resistance, then again, that's something that I don't want to say I told you, and if something bad were to happen, you come back here with a fury of Caps Lock.
But yeah, that's the best help I can give you with what I've got here, I'd say just take some pictures, or even a youtube video or something, could always help us.
If the bolt is locking in place, maybe a sear got too far up into it, and perhaps you need to look at your trigger assembly before mounting it, but maybe you need to try with a little bit more resistance, then again, that's something that I don't want to say I told you, and if something bad were to happen, you come back here with a fury of Caps Lock.
But yeah, that's the best help I can give you with what I've got here, I'd say just take some pictures, or even a youtube video or something, could always help us.